Centrifugal breather



United States Patent O CENTRIFUGAL BREATHER Robert I. Powell, Muskegon, Mich., assignor to Continental Motors Corporation, Detroit and Muskegon, Mich., a corporation of Virginia Application November 22, 1954, Serial No. 470,351

9 Claims. (Cl. 121-194) My invention relates to internal combustion engines and more particularly to a crankcase breather structure therefor.

A crankcase breather is a necessary and essential element for etlicient engine operation and many types and designs are available. All usually comprise valving or other means for separating the heavier particles from the crankcase vapors, and all such devices usually ernploy engine suction pressures for their operation. However, these breathers quite often become clogged or the moving parts become stuck or otherwise inoperable.

It is an object of my present invention to overcome the difficulties encountered with the conventional crankcase breathers by the design and construction of a crankcase breather structure with no moving parts, and more particularly by constructing same as a coacting structure with no moving parts, and more particularly by constructing same with a rotating engine element to thereby utilize centrifugal forces for separating the heavier particles from said crankcase vapors.

yFor a more detailed understanding of my invention, reference may be had to the accompanying drawing illustrating a preferred embodiment of my invention, and in which: v

Fig. 1 is a fragmentary longitudinal sectional view of an internal combustion engine illustrating my novel crankcase breather structure, and

Fig. 2 is a transverse sectional View taken substantially on the line 2-2 of Fig. l.

My improved crankcase breather structure is herein illustrated in connection with a fragmentary sec-tion of an internal combustion engine, and more particularly shown as embodied land cooperatively -assembled with the engine crankshaft. It will be obvious that while I have chosen to illustrate the invention with an engine crankshaft, the principle of my invention may be associated with other rotating engine elements if so desired.

The engine comprises a crankcase 10, the interior 11 of which accumulates vapors which carry oil and fuel particles in suspension, which in due course of engine operation are sometimes lost. The reference character 12 designates the engine crankshaft, which shaft usually comprises a hollow shaft at the ends to minimize weight while giving strength. This engine crankshaft as herein illustrated is provided with .a bore 13 open at both ends to the crankcase interior, the inner open end serving as the main communication between the hollow shaft and the crankcase interior. This crankshaft is supported in bearings carried by the crankcase in the conventional manner and drives gears for operating various conventional engine accessories.

The crankcase is provided `with an opening 14 in line with the crankshaft, and a casting 15 is secured f thereto, closing said opening 14. The casting 15 is provided with an outlet 16 preferably opening to the atmosphere.

A tubular section 17, here shown as a pair of co-ex 2,818,047 Patented Dec. 31,V 1957 wise permanently secured together. The tube 17b is closed at the inner end by the cap or end closure portion 18 and is provided with a plurality of openings 19, which place the interior of the tube in open communication with the bore 13 of the crankshaft 12. An annular flange or baffle 20 carried by the tubular section 17 is disposed intermediate the outlet 16 and openings 19, said baille substantially lling the bore 13 but arranged preferably with a slight clearance so as to not scrape on the rotating crankshaft. The tubes 17a and 17b are of a diameter appreciably less than the internal diameter of the bore 13 of said hollow crankshaft to space the walls of said tubes from the sides of the bore 13.

In operation the crankcase vapors are caused to flow into bore 13, are then dispersed radially outwardly as shown by arrows 25 and are then turned radially inwardly when flowing through openings 19 into the tube 17b. The centrifugal forces produced by the rotating crankshaft on said crankcase vapors throws the heavier particles of matter, mostly oil held in suspension in said vapor, radially outward where same is collected on the inside wall of the bore 13 and subsequently drained back into the crankcase, while the lighter vapor, free of these heavier particles, passes through openings 19 into the -tube 17b, thence through tube 17a and to the outlet 16. The closure or cap 18 of tube 17h is preferably coneshaped, as shown to more efficiently outwardly disperse the crankcase vapors.

It may thus be noted that the only moving part of this crankcase breather structure is the rotating engine element, which in the embodiment shown, comprises the engine crankshaft. The xed tubes and outlet casting to which said tubular structure is secured may, if desired, be similarly assembled with any one of several engine rotating elements, which may conveniently be used.

It will be apparent to those skilled in the art to which my invention pertains that various changes and modifications may be made herein without departing from the spirit of my invention or from the scope of the appended claims.

l claim:

1. In an internal combustion engine having a crankcase, a crankshaft rotatably supported by said crankcase,

case interior, and a breather element secured to said crankcase and comprising `a hollow tubular extension extending approximately half-way into the said crankshaft bore and provided with openings in the cylindrical wall thereof for placing the interior of said tubular extension in open communication with substantially the greater part of the said crankshaft bore, said element having an outlet, the vapor from said crankcase being caused to flow into the crankshaft bore whereby the heavier particles are separated from the vapor in the said crankshaft bore by centrifugal action and accumulated on the walls of the crankshaft bore and subsequently returned to the crankcase, While said lighter vapor is conducted through said tubular extension to the aforesaid outlet.

2. In an internal combustion engine having a crankcase, a crankshaft rotatably supported by said crankcase, said crankshaft having an axially longitudinally extending bore provided with a centrally axially disposed inlet opening at one end in direct communication with the crankcase interior, and a breather element secured to said crankcase and having a hollow tubular extension extending approximately half way into the said crankshaft bore and provided with openings in the cylindrical wall thereof for placing the interior of said tubular extension in open communication with substantially the greater part of the said crankshaft bore, said element having an outlet, the vapor from said crankcase being caused to flow into the crankshaft bore whereby the heavier particles are separated from the vapor in said crankshaft bore by centrifugal action and accumulated on the walls of the crankshaft bore enclosing the stationary tubular extensionk and returned to the crankcase, while said lighter vapor is conducted through said tubular extension to the aforesaid outlet, said tubular extension closed at its inner end and said vapor constrained to flow radially inwardly through the openings in said extension whereby to separate the heavier particles therefrom by centrifugal forces.

3. A crankcase breather structure for an internal combustion engine having a crankcase and a rotating element having an axially longitudinally extending bore provided with a centrally axially disposed inlet opening in direct communication with the crankcase interior, said breather structure comprising a header fixed to the crankcase, a tubular extension carried by the header and extended approximately half way into the bore of said rotating engine element, said header having an outlet, and said tubular extension having openings in the cylindrical wall thereof which place the interior thereof in open cornmunication with substantially the greater part of the bore of said rotating engine element, the crankcase vapors confined to flow into said bore of the rotating element and then to be turned to flow radially inwardly through the openings in said tubular extension whereby to separate the heavier particles from the crankcase vapors in said rotating engine element by centrifugal forces generated by rotation of the rotating engine element, said lighter vapors passing through the tubular extension to said outlet, said heavier particles being deposited on the walls of the bore of said rotating engine element and thence drained back in said crankcase.

4. A cranltcase breather structure for an internal combustion engine having a crankcase and a rotating element having an axially longitudinally extending bore provided with a centrally axially disposed inlet opening in direct communication with the crankcase interior, said breather structure comprising a header secured to the crankcase, a tubular extension carried by the header and extended approximately half way into the bore of said rotating engine element, said header having an outlet, and said tubular extension having openings in the cylindrical wall thereof which place the interior thereof in open cornmunicaton with substantially the greater part of the bore ofsaid rotating engine element, the crankcase vapors confined to ow into said bore and then be turned to flow radially inwardly through the -openings in said stationary tubular extension whereby to separate the heavier particles from the crankcase vapors by centrifugal forces generated by rotation of the rotating engine element, said lighter vapors passing through the tubular extension to said outlet, said heavier particles being deposited on the walls of the bore of said rotating engine element and thence drained back in said crankcase, said tubular extension having an external ange intermediate the outlet and the openings whereby to baie the cranltcase vapors and induce flow thereof substantially only through the openings aforesaid.

5. In an internal combustion engine having a crankcase and a hollow rotating engine element having a centrally axially disposed inlet opening in direct communication with the crankcase interior, a crankcase breather structure comprising a vapor duct secured to the crankcase and assembled approximately half way into said hollow rotating engine element and operable to utilize the centrifugal forces induced within and by said rotating element to separate the heavier* particles from the crankcase vapors prior to introduction of said vapor to sad'vapor duct, said'vapor-duct provided with inletopen- 4 ings in the cylindrical wall thereof and with an outlet open to the atmosphere.

6. In an internal combustion engine having a crankcase and a hollow rotating engine element having a centrally axially disposed inlet opening in direct communication with the crankcase interior, a crankcase breather structure comprising a vapor duct secured to the crankcase and assembled approximately half way into the hollow rotating engine element and operable to utilize the centrifugal forces induced within and by said rotating element to separate the heavier particles from the crankcase vapors prior to introduction of same to said vapor duct, said vapor duct provided with inlet openings in the cylindrical wall thereof and with an outlet open to the atmosphere, saidvapor duct comprising a tubular duct axially and concentrically positioned in the hollow engine rotating element.

7. In an internal combustion engine having a crankcase and a hollow rotating engine element having a centrally axially disposed inlet opening in direct communication with the erankcase interior, a crankcase breather structure comprising a vapor duct secured to the crankcase and assembled approximately half way into said hollow rotating engine element and operable to utilize the centrifugal forces induced within and by said rotating element to separate the heavier particles from the crankcase vapors in said bore and prior to introduction of same to said vapor duct, said vapor duct provided with an outlet open to the atmosphere, said vapor duct comprising a tubular duct axially and concentrically positioned in the hollow engine rotating element, said duct having a diameter less than the interior diameter of the hollow rotating engine element and a plurality of holes in the cylindrical wall thereof and communicating the interior thereof with the interior of said rotating element and an annular flange between said holes and the outlet to baffle the crankcase vapors to facilitate and guide the flow of said vapor into said vapor duct.

8. In an internal combustion engine having a crankcase and a hollow rotating engine element having a centrally axially disposed inlet opening in direct communication with the crankcase interior, a crankcase breather structure comprising a vapor duct secured to the crankcase and assembled approximately half way into said hollow rotating engine element and operable to utilize the centrifugal forces induced within and by said rotating element to separatev the heavier particles from the crankcase vapors prior to introduction of same to said vapor duct, said vapor duct provided with an outlet open to the atmosphere, said vapor duct comprising a tubular duct axially and concentrically positioned in the hollow engine rotating element, said duct having a diameter less than the internal diameter of the hollow rotating engine element and a plurality of holes in the cylindrical wall thereof and communicating the interior thereof with the interior of said rotating element and an annular ange between said holes and the outlet to baiile the crankcase vapors to facilitate and guide the ow of said vapor into said vapor duct, said extreme inner end of the tubular duct being closed.

9. In an internal combustion engine having a crankcase and a hollow rotating engine element having a centrally axially disposed inlet opening in direct communication with the crankcase interior, a crankcase breather structure comprising a vapor duct secured to the crankcase and assembled approximately half way into said hollow rotating engine element and operable to utilize the centrifugal forces induced within and by said rotating element to separate the heavier particles from the crankcase vapors prior to the introduction of same to said vapor duct, said vapor duct provided with an outlet, said vapor duct comprising a tubular duct axially and con centrically positioned in the hollow engine rotating element, said duct having a diameter. less than the internal diameter of the hollow rotating engine element and a plurality of holes communicating the interior thereof with the interi-or of said rotating element and an annular ange between said holes and the outlet to baille the crankcase vapors to facilitate ow of said vapor into said vapor duct, and a closure for the extreme inner end of the tubular duct comprising a conical cap portion with the apex thereof facing the incoming ow of the crankcase vapors.

References Cited in the le ofthis patent UNITED STATES PATENTS Levedahl et al July 6, 1926 Levedahl et al July 6, 1926 Chilton Sept. 25, 1934 Carvelli Oct. 30, 1934 Bourke Sept. 12, 1939 

